Emerging role of bacteria in oral carcinogenesis: a review with special reference to perio-pathogenic bacteria

A novel prognostic index for oral squamous cell carcinoma patients with surgically treated

This study aims to develop an applicable prognostic index with conventional factors for predicting outcome of patients with oral squamous cell carcinoma (OSCC). We performed a prospective study in a large cohort of 892 OSCC patients in Fujian, China. All patients were randomly divided into a discovery group and validation group. A prognostic index was developed based on β value of each significant variable obtained from the multivariate Cox regression model. The results from discovery and validation set demonstrated thatthe model-4(included clinical stage, tumor differentiation, ill-fitting denture, oral hygiene and cigarette smoking) was the optimal model. The optimal cutoff points of prognostic index (1.88 and 2.80) were determined by X-tile program which categorized all subjects into low, middle and high risk subsets. Patients in high risk group were at the greatest risk of death compared with those in low risk group (HR: 6.02; 95%CI: 4.33-8.38). Moreover, there was a significant tendency of the worse overall survival with the higher prognostic index (Ptrend <0.001). The discriminatory capacity of prognostic index was 0.661(95%CI: 0.621-0.701). This study developed and validated a prognostic index that is an economical and useful tool for predicting the clinical outcomes of OSCC patients in Southeast China. Future randomized trials with larger cohort are required to confirm our results.

Periodontal Disease and Incident Cancer Risk among Postmenopausal Women: Results from the Women's Health Initiative Observational Cohort

Background: Periodontal pathogens have been isolated from precancerous and cancerous lesions and also shown to promote a procarcinogenic microenvironment. Few studies have examined periodontal disease as a risk factor for total cancer, and none have focused on older women. We examined whether periodontal disease is associated with incident cancer among postmenopausal women in the Women's Health Initiative Observational Study.Methods: Our prospective cohort study comprised 65,869 women, ages 54 to 86 years. Periodontal disease information was obtained via self-report questionnaires administered between 1999 and 2003, whereas ascertainment of cancer outcomes occurred through September 2013, with a maximum follow-up period of 15 years. Physician-adjudicated incident total cancers were the main outcomes and site-specific cancers were secondary outcomes. HRs and 95% confidence intervals (CI) were calculated using Cox proportional hazards regression. All analyses were conducted two-sided.Results: During a mean follow-up of 8.32 years, 7,149 cancers were identified. Periodontal disease history was associated with increased total cancer risk (multivariable-adjusted HR, 1.14; 95% CI, 1.08-1.20); findings were similar in analyses limited to 34,097 never-smokers (HR, 1.12; 95% CI, 1.04-1.22). Associations were observed for breast (HR, 1.13; 95% CI, 1.03-1.23), lung (HR, 1.31; 95% CI, 1.14-1.51), esophagus (HR, 3.28; 95% CI, 1.64-6.53), gallbladder (HR, 1.73; 95% CI, 1.01-2.95), and melanoma skin (HR, 1.23; 95% CI, 1.02-1.48) cancers. Stomach cancer was borderline (HR, 1.58; 95% CI, 0.94-2.67).Conclusions: Periodontal disease increases risk of total cancer among older women, irrespective of smoking, and certain anatomic sites appear to be vulnerable. Impact: Our findings support the need for further understanding of the effect of periodontal disease on cancer outcomes. Cancer Epidemiol Biomarkers Prev; 26(8); 1255-65. ©2017 AACR.

Inflammatory bacteriome featuring Fusobacterium nucleatum and Pseudomonas aeruginosa identified in association with oral squamous cell carcinoma

Studies on the possible association between bacteria and oral squamous cell carcinoma (OSCC) remain inconclusive, largely due to methodological variations/limitations. The objective of this study was to characterize the species composition as well as functional potential of the bacteriome associated with OSCC. DNA obtained from 20 fresh OSCC biopsies (cases) and 20 deep-epithelium swabs (matched control subjects) was sequenced for the V1-V3 region using Illumina’s 2 × 300 bp chemistry. High quality, non-chimeric merged reads were classified to species level using a prioritized BLASTN-algorithm. Downstream analyses were performed using QIIME, PICRUSt, and LEfSe. Fusobacterium nucleatum subsp. polymorphum was the most significantly overrepresented species in the tumors followed by Pseudomonas aeruginosa and Campylobacter sp. Oral taxon 44, while Streptococcus mitis, Rothia mucilaginosa and Haemophilus parainfluenzae were the most significantly abundant in the controls. Functional prediction showed that genes involved in bacterial mobility, flagellar assembly, bacterial chemotaxis and LPS synthesis were enriched in the tumors while those responsible for DNA repair and combination, purine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, ribosome biogenesis and glycolysis/gluconeogenesis were significantly associated with the controls. This is the first epidemiological evidence for association of F. nucleatum and P. aeruginosa with OSCC. Functionally, an “inflammatory bacteriome” is enriched in OSSC.